From: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Subject: mm, page_alloc: restore the original nodemask if the fast path allocation failed The page allocator fast path uses either the requested nodemask or cpuset_current_mems_allowed if cpusets are enabled. If the allocation context allows watermarks to be ignored then it can also ignore memory policies. However, on entering the allocator slowpath the nodemask may still be cpuset_current_mems_allowed and the policies are enforced. This patch resets the nodemask appropriately before entering the slowpath. Link: http://lkml.kernel.org/r/20160504143628.GU2858@xxxxxxxxxxxxxxxxxxx Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 6 ++++++ 1 file changed, 6 insertions(+) diff -puN mm/page_alloc.c~mm-page_alloc-restore-the-original-nodemask-if-the-fast-path-allocation-failed mm/page_alloc.c --- a/mm/page_alloc.c~mm-page_alloc-restore-the-original-nodemask-if-the-fast-path-allocation-failed +++ a/mm/page_alloc.c @@ -3636,6 +3636,12 @@ retry_cpuset: alloc_mask = memalloc_noio_flags(gfp_mask); ac.spread_dirty_pages = false; + /* + * Restore the original nodemask if it was potentially replaced with + * &cpuset_current_mems_allowed to optimize the fast-path attempt. + */ + if (cpusets_enabled()) + ac.nodemask = nodemask; page = __alloc_pages_slowpath(alloc_mask, order, &ac); no_zone: _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
